Typical rotary mowers have a horizontally oriented mower deck mounted on wheels for movement along the ground and a horizontally oriented rotating blade mounted under the deck. Wider rotary mowers typically include a center deck with right and left wing decks pivotally attached to the center deck about horizontal wing pivot axes oriented substantially in alignment with an operating travel direction of the mower. For transport the wings are pivoted up about the wing pivot axes to a generally vertical transport position. One or more rotating blades are mounted under each wing deck.
These wider rotary mowers are typically supported on front and rear wheels and are towed by a tractor connected to the front end of a hitch arm extending forward from the mower. The blades are commonly driven by the power take-off of the towing tractor connected by driveshafts to gearboxes mounted on the tops of the decks for example as shown in U.S. Pat. Nos. 7,775,024 and 6,854,250 to Boyko. It is also known to drive the blades with hydraulic motors powered by the tractor hydraulic supply or by a separate hydraulic pump mounted on the mower and driven by the tractor's power take off, for example as disclosed in U.S. Pat. No. 5,511,368 to Kocher.
Such wider rotary mowers are often used for cutting on ditches alongside roads. Such ditches are sloped and are also are periodically crossed by approaches which allow access to the road across the ditch. To allow the towing tractor to drive on the road surface with the mower pulled behind in an offset position on the sloped ditch surface, the hitch arms of the Boyko '024 and '250 mowers pivot with respect to the mower so the mower trails the tractor in the desired offset position. The Kocher mower can be operated while located in a variety of positions relative to the tractor as well.
Obstructions, such as road approaches in the ditches, can be quite steep and sharply sloped. The wider mowers usually used for ditch cutting have quite long hitch members extending forward from the mower to the tractor to provide for sufficient offset. These hitch arms often drag on these obstructions as the tractor moves sharply up and down relative to the mower. On both of the Boyko '024 and '250 mowers, the hitch extends upward from the tractor attachment end and then rearward and down to the mower providing a raised hitch that provides increased clearance thus reducing the contact of the hitch with approaches and the like.